multer-gridfs error " TypeError: Cannot read properties of undefined (reading '_id') "

Question

I'm working on creating a WhatsApp clone and implementing a file sharing feature. Everything was going smoothly until I encountered this error that's causing my backend to crash. The strange thing is, I can see the file in MongoDB, but the error persists. I'm hoping someone can help me troubleshoot this issue.

Here's a summary of what's happening:

I have a file sharing feature in my WhatsApp clone app. When a user tries to share a file, it's saved to MongoDB. I can confirm that the file exists in the MongoDB database. However, the backend crashes with an error that I can't seem to resolve. I'm not sure where to begin troubleshooting this issue. Can anyone provide insights on what might be causing this problem? Is there a common mistake I might be making when dealing with file sharing in a MongoDB database?

i cant post all my code here my question will be too long [here is my github link][1]

api.js

export const uploadFile = async (data) => {
    try {
        return await axios.post(`${url}/file/upload`, data);
    } catch (error) {
        console.log('Error while calling uploadfile API ', error);
    }
}

controller

const url = 'http://localhost:8000';
export const uploadFile = async(request, response)=>{
    if(!request.file){
        return response.status(404).json("file not found")
    }
    const imageUrl = `${url}/file/${request.file.filename}`;
    return response.status(200).json(imageUrl);
}

route.js

//Route for file upload
route.post('/file/upload', upload.single("file"), uploadFile);

error

C:\Users\user\OneDrive\Documents\webdev\whatsapp clone self\server\node_modules\multer-gridfs-storage\lib\gridfs.js:306
                        id: f._id,
                              ^

TypeError: Cannot read properties of undefined (reading '_id')       
    at GridFSBucketWriteStream.emitFile (C:\Users\Siddh\OneDrive\Documents\webdev\whatsapp clone self\server\node_modules\multer-gridfs-storage\lib\gridfs.js:306:31)
    at GridFSBucketWriteStream.emit (node:events:526:35)
    at finish (node:internal/streams/writable:807:10)
    at process.processTicksAndRejections (node:internal/process/task_queues:82:21)

Node.js v20.9.0
[nodemon] app crashed - waiting for file changes before starting...

Answer 1

Title: Solution for multer-gridfs error "TypeError: Cannot read properties of undefined (reading '_id')"

Answer:

It appears that you're encountering an issue with multer-gridfs that could be related to compatibility with your MongoDB version. To resolve this problem, consider downgrading your MongoDB version to one that is compatible with multer and multer-gridfs. Here's a step-by-step guide:

1. Uninstall MongoDB:

npm uninstall MongoDB

2. Install Compatible Version (e.g., 5.9.1):

npm install [email protected]

This should help resolve the "TypeError: Cannot read properties of undefined (reading '_id')" issue you're facing. Ensure to restart your Node.js application after making these changes.

Additionally, it's essential to check the compatibility matrix of multer-gridfs with MongoDB versions. Upgrading or downgrading packages can sometimes introduce other compatibility issues, so it's recommended to review the documentation and release notes for both multer-gridfs and MongoDB.

If the problem persists or if you encounter any other issues during the process, feel free to provide more details or ask for further assistance.

Answer 2

Its seems that the multer is not compatible with the latest mongodb so in your backend folder install the mongodb version 5.9.1 npm i [email protected]

for more info see https://github.com/devconcept/multer-gridfs-storage/issues/560